No link on empty page in wp_list_pages

Question

Currently I'm using

<?php wp_list_pages( 'post_type=region&title_li=' ); ?>

To get the hierarchical list of my custom posts 'region'. It works perfectly. I got this :

• Europe
  • Belgium
  • France
• Asia
  • China

With a link on each item. BUT some pages have no content. It's just there to create the hierarchy. In this example, ASIA has no content.

So I'd like a way to create this menu list but if the page has no content -> no link for this element.

So I suppose, I need to use another way than wp_list_pages. But which one ?

Can you help me ?

Thank you !

Answer 1

wp_list_pages() uses a walker named Walker_Page to render its output and this can be overridden.

Below is a customized version of Walker_Page::start_el(). The code was first copied from the core, then a simple check was added before outputting the link. If a post does not have any content, then the title is wrapped in a <span> tag rather than an <a>.

Here, the modification is highlighted:

    ...
    // Modification: If a posts content is empty, do not link the item. Instead use a span tag to wrap the text.
    $maybe_link_item = empty( $page->post_content ) ? '<li class="%s"><span class="no-link">%3$s%4$s%5$s</span>' : '<li class="%s"><a href="%s">%s%s%s</a>';

    $output .= $indent . sprintf(
        $maybe_link_item, // Modification: Using this variable instead of '<li class="%s"><a href="%s">%s%s%s</a>'
        $css_classes,
        get_permalink( $page->ID ),
        $args['link_before'],
        /** This filter is documented in wp-includes/post-template.php */
        apply_filters( 'the_title', $page->post_title, $page->ID ),
        $args['link_after']
    );
    ...

Here is the full walker:

class WPSE_Walker_Page extends Walker_Page {
    // Copied from Walker_Page::start_el() core version v4.7.4.
    /**
     * Outputs the beginning of the current element in the tree.
     *
     * @see Walker::start_el()
     * @since 2.1.0
     * @access public
     *
     * @param string  $output       Used to append additional content. Passed by reference.
     * @param WP_Post $page         Page data object.
     * @param int     $depth        Optional. Depth of page. Used for padding. Default 0.
     * @param array   $args         Optional. Array of arguments. Default empty array.
     * @param int     $current_page Optional. Page ID. Default 0.
     */
    public function start_el( &$output, $page, $depth = 0, $args = array(), $current_page = 0 ) {
        if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
            $t = "\t";
            $n = "\n";
        } else {
            $t = '';
            $n = '';
        }
        if ( $depth ) {
            $indent = str_repeat( $t, $depth );
        } else {
            $indent = '';
        }

        $css_class = array( 'page_item', 'page-item-' . $page->ID );

        if ( isset( $args['pages_with_children'][ $page->ID ] ) ) {
            $css_class[] = 'page_item_has_children';
        }

        if ( ! empty( $current_page ) ) {
            $_current_page = get_post( $current_page );
            if ( $_current_page && in_array( $page->ID, $_current_page->ancestors ) ) {
                $css_class[] = 'current_page_ancestor';
            }
            if ( $page->ID == $current_page ) {
                $css_class[] = 'current_page_item';
            } elseif ( $_current_page && $page->ID == $_current_page->post_parent ) {
                $css_class[] = 'current_page_parent';
            }
        } elseif ( $page->ID == get_option('page_for_posts') ) {
            $css_class[] = 'current_page_parent';
        }

        /**
         * Filters the list of CSS classes to include with each page item in the list.
         *
         * @since 2.8.0
         *
         * @see wp_list_pages()
         *
         * @param array   $css_class    An array of CSS classes to be applied
         *                              to each list item.
         * @param WP_Post $page         Page data object.
         * @param int     $depth        Depth of page, used for padding.
         * @param array   $args         An array of arguments.
         * @param int     $current_page ID of the current page.
         */
        $css_classes = implode( ' ', apply_filters( 'page_css_class', $css_class, $page, $depth, $args, $current_page ) );

        if ( '' === $page->post_title ) {
            /* translators: %d: ID of a post */
            $page->post_title = sprintf( __( '#%d (no title)' ), $page->ID );
        }

        $args['link_before'] = empty( $args['link_before'] ) ? '' : $args['link_before'];
        $args['link_after'] = empty( $args['link_after'] ) ? '' : $args['link_after'];

        // Modification: If a posts content is empty, do not link the item. Instead use a span tag to wrap the text.
        $maybe_link_item = empty( $page->post_content ) ? '<li class="%s"><span class="no-link">%3$s%4$s%5$s</span>' : '<li class="%s"><a href="%s">%s%s%s</a>';

        $output .= $indent . sprintf(
            $maybe_link_item, // Modification: Using this variable instead of '<li class="%s"><a href="%s">%s%s%s</a>'
            $css_classes,
            get_permalink( $page->ID ),
            $args['link_before'],
            /** This filter is documented in wp-includes/post-template.php */
            apply_filters( 'the_title', $page->post_title, $page->ID ),
            $args['link_after']
        );

        if ( ! empty( $args['show_date'] ) ) {
            if ( 'modified' == $args['show_date'] ) {
                $time = $page->post_modified;
            } else {
                $time = $page->post_date;
            }

            $date_format = empty( $args['date_format'] ) ? '' : $args['date_format'];
            $output .= " " . mysql2date( $date_format, $time );
        }
    }
}

To use the new walker, add it to your theme's functions.php or to a plugin, then modify the call to wp_list_pages() so that it uses our new custom walker:

    wp_list_pages( [
        'post_type' => 'region',
        'walker'    => new WPSE_Walker_Page(),
        'title_li'  => '',
    ] );